Alfalfa fields may periodically exhibit yellow foliage. This publication addresses several of the possible problems behind the yellowing, including leaf spot diseases, root rots, crown rots, potassium deficiency, poor nodulation, soil compaction, and potato leafhopper injury. Symptom descriptions and color photos can aid in diagnosis.
Possible Causes of Yellowing Alfalfa (PPFS-AG-F-10) is available online.
For additional publications on forage diseases, visit the UK Plant Pathology Extension Publications webpage.
By Kiersten Wise, Extension Plant Pathologist